Heretofore, a method of culturing adherent cells and suspension cells of mammals in vitro is known. Such culture has been performed in culture vessels typified by a flask and a Petri dish formed with glass or synthetic resin, for example. In general, many of such culture vessels have a small capacity, and thus are not suitable for mass culture.
On the other hand, a bag-shaped cell culture vessel has been devised as a vessel for culturing floating cells (Patent Literatures 1 to 3). In the cell culture vessel, a sealed space capable of sealing a culture medium by bonding synthetic resin sheets to each other is formed thereinside. A culture medium and a cell floating liquid can be made to flow into/out of the sealed space through a port. Moreover, a bag-shaped cell culture vessel suitable for culture of adherent cells has also been devised (Patent Literature 4).